JPH01297242A - Optical material - Google Patents

Abstract

PURPOSE:To impart a high refractive index and to enhance colorless transparency, heat resistance and scratch resistance, by providing a cured film layer to the surface of a high refractive index transparent resin base material composed of a polymer containing polyfunctional thioacrylate or thiomethacrylate as an essential component and further containing another polymerizable monomer radical-copolymerizable therewith if necessary. CONSTITUTION:A cured film layer is provided to the surface of a high refractive index resin base material composed of a polymer obtained from polymerizable monomer components containing one or more kind of a polyfunctional thioacrylate or thiomethacrylate polymerizable monomer I as an essential component and further containing a polymerizable monomer II radical-copolymerizable with said polymerizable monomer I if necessary. As the polymerizable monomer I, there is no limit as if one having at least one thioester group and two polymerizable unsaturated groups in the molecule thereof is used. The polymerizable monomer I imparts a high refractive index and a crosslinked structure to a polymer and has excellent heat resistance and hardly generates fusion or clogging at the time of cutting or lens-lapping processing.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an optical material having a cured coating layer on the surface of a novel high refractive index transparent resin substrate.

<Prior art> In recent years, colorless and transparent plastic materials have been used for optical components such as lenses, prisms, and optical waveguides, mirrors made of sheets with a coating on the back side, and sheets containing pigments, vehicles, and ships. It has also come to be widely used as a decorative material in the field of architecture, as a building material, and as a glazing material for automobiles.

In general, plastic optical materials have superior characteristics such as being lighter and less likely to break than inorganic glass, but have problems in that they have a low refractive index and are inferior in abrasion resistance and scratch resistance. Such defects in abrasion resistance and scratch resistance not only cause a decrease in transparency and aesthetic appearance, but also ultimately cause the material to lose its function as an optical material. In order to prevent this, the surface of the plastic substrate is usually treated with an iK hard coat.

On the other hand, it is desirable that the material used to manufacture the optical material has a high refractive index. For example, in the case of a lens, a material with a high refractive index allows the lens to be made thinner than a material with a low refractive index in order to maintain the same focal length. Using thin lenses can reduce the volume of space occupied by the lenses in the optical assembly;
This provides the advantage of reducing the weight and size of the optical device. In addition, lenses for eyeglasses made from materials with a high refractive index have the advantage of being thinner and lighter, making them more fashionable.

<Problems to be Solved by the Invention> However, it cannot be said that the plastic materials conventionally used as optical materials can fully satisfy these points. For example, diethylene glycol bisallyl carbonate resin (hereinafter referred to as ADC resin), polymethyl methacrylate (hereinafter referred to as PMMA), polycarbonate (hereinafter referred to as PC), etc. are colorless and transparent, and are generally used as optical materials for plastics. However, ADC resin and PMMA have a refractive index of 1.49.
~1.50, which is small. Also, pc has a refractive index of 1.58 to 1.
．． Although it has a high value of 59, birefringence is likely to occur during molding, which causes problems with optical uniformity.In addition, special primers and pretreatment are required due to poor adhesion with the hard coat layer, and the resin itself is soft and easily scratched. It had the disadvantage of being easy to stick to. Therefore, it is desired to develop an optical material made of plastic material that has the above-mentioned drawbacks improved.

The purpose of the present invention is to maintain the advantages of light weight and colorless transparency, which are the advantages of plastic materials conventionally used for optical materials, while also improving the disadvantages thereof. As a result of repeated efforts, an optical material with a cured film layer on the surface of a resin base material obtained by using a sulfur-containing polymerizable monomer with a specific structure as an essential component has solved the above problems and has a high refractive index. The inventors have discovered that this material has excellent colorless transparency, heat resistance, and abrasion resistance, leading to the completion of the present invention.

That is, the present invention includes one or more polyfunctional thioacrylates or thiomethacrylates (hereinafter referred to as polymerizable monomer [I]) as an essential component, and if necessary, the polymerizable monomer [I] and radicals. Other copolymerizable monomers (
The present invention relates to an optical material characterized in that a cured film layer is formed on the surface of a high refractive index resin base material made of a polymer obtained from a polymerizable monomer component containing n).

In the present invention, the polymerizable monomer CI) is not particularly limited as long as it has at least one thioester group and two or more polymerizable unsaturated groups in the molecule, but may be of the following general formulas (1) to ( It is preferable to use a polyfunctional thioacrylate or methacrylate shown in 3) because a (co)polymer having a high refractive index and excellent heat resistance can be obtained.

(Note) General formula (1) (However, R, O and R7 are H, CHs, Rs
Oyobi R4 is each independently H%CHs or OH,
and m are each independently an integer of 1 to 5, l and n
are each independently O or an integer from 1 to 4. ) General formula (2) (However, R,, R1 and k are the same as in general formula (1), and X is 0 or S.) General formula (3) % formula % (However, R , and R are the same as in general formula (1) K, and Rt is a phenylene group, a xylylene group, a phenylene group substituted with a nucleus, or a xylylene group.) In general formulas (1) to (3), As the corresponding polymerizable monomer [I], for example, [hereinafter, R also represents H or CH]
S-2-Acryloyloxyethylthio(meth)acrylate OO 8-2-Methacryloyloxyethylthio(meth)acrylate RR 1,2-bis((meth)acryloylthio)ethane RR 1! CHm0 1.2-bis((meth)acryloylthio)propane R
R 1,3-his((meth)acryloylthio)propane R
R 1,4-bis((meth)acryloylthio)butane RR II o O bis-(2-(
meth)acryloylthioethyl)ether O bis-(2-(meth)acryloylthioethyl)sulfide RR CH* =C-C-8CHtCHzOCHz 0CHt
CHt S -C-C=CH20゜bis-(2-(meth)acryloylthioethoxy)methane RR bis-(2-(meth)acryloylthioethylthio)methane RR o 01.2-bis-(2-(meth)acryloylthioethoxy)methane ) acryloylthioethoxy)ethane OO l, 2-bis-(2-(meth)acryloylthioethylthio)ethane RR bis-(2-(2-(meth)acryloylthioethoxy)ethyl)ether RR bis-(2- (2-(meth)acryloylthioethylthio)ethyl)sulfide 1.4-bis((meth)acryloylthio)benzene 1
．． Examples include, but are not limited to, 4-bis((meth)acryloylthiomethyl)benzene.

The high refractive index resin that is the base material of the optical material provided by the present invention may be made of a polymer obtained using only one or more polymerizable monomers (1). However, it may also be a polymer obtained by using another polymerizable monomer (II) as a copolymerization component if necessary. Other polymerizable monomers that can be used are not particularly limited as long as they can be radically copolymerized with polymerizable monomer [I], and do not fall under monofunctional monomers or polymerizable monomers (1). In addition to polyfunctional monomers, polymerizable polymers collectively called oligomers can be used, and homopolymers preferably have a refractive index of 1.48 or more.

Polymerizable monomers (ID examples include monofunctional acrylic esters and methacrylic esters, polyfunctional acrylic esters and methacrylic enosters, 2-halogen≠acrylic esters, monofunctional thioacrylic esters and thio Examples include methacrylic acid esters, unsaturated nitriles, acrylamide and methacrylamide, allyl esters, allyl ethers and allyl carbonates, vinyl aromatics, reactive oligomers, etc., and one or more of these It is possible to use

In the high refractive index resin that is the base material of the optical material provided by the present invention, the polymerizable monomer CI) imparts a high refractive index and a crosslinked structure to the polymer, and therefore has excellent heat resistance and is suitable for cutting. It is used to obtain a (co)polymer as a high refractive index transparent resin base material that is less likely to cause fusion or clogging during processing of molds or molds, and that prevents resin components from adhering to processing tools. In order to fully exhibit such characteristics, the amount of polymerizable monomer (1) used is preferably 5% by weight or more, more preferably 10% by weight or more in the polymerizable monomer component.

If the amount is less than 5 weight i%, the contribution of the polymerizable monomer CI) to a high refractive index will be small, and the crosslinking density will be small, which will have an effect on improving heat resistance, cutting workability, soil tank workability, etc. is small.

The type and amount of the polymerizable monomer C11) are selected as necessary, taking into consideration the refractive index of the high refractive index resin to be obtained. In obtaining the resin, it is preferable that the amount used is less than 95% by weight, more preferably less than 90% by weight, based on the monomer component.

The (co)polymer used as the high refractive index transparent resin base material in the optical material provided by the present invention contains the polymerizable monomer (1) as an essential component, and optionally contains the polymerizable monomer (II). This is achieved by radically polymerizing the polymerizable monomer components contained therein to form a high refractive index resin. The method of radical polymerization is not particularly limited, and conventionally well-known methods can be adopted, but specific examples include, for example, radical polymerization of polymerizable monomer components in the presence of an initiator. Examples include a method of heat polymerization, (1) a method of polymerizing a polymerizable monomer component with ultraviolet rays in the presence of a photosensitizer, and (2) a method of polymerizing a polymerizable monomer component with electron beams.

Method (2) is the most common method, and the equipment is simple and the radical polymerization initiator is relatively inexpensive.

In the case of method (2), the curing speed is fast and the polymerization time can be shortened.

In the method (2), since polymerization can be performed even in the absence of a radical polymerization initiator or a photosensitizer, it is also possible to reduce the amount of impurities mixed into the high refractive index resin.

In the present invention, which of the methods (1) to (4) is used may be appropriately selected depending on the desired performance of the high refractive index resin, and in some cases, a plurality of methods may be combined.

The high refractive index transparent resin used for the base material of the optical material provided by the present invention may appropriately contain known additives such as ultraviolet absorbers, antioxidants, drip-proofing agents, colorants, and the like.

The cured film layer formed on the surface of the high refractive index transparent resin base material in the present invention can be made of various coating agents that have been conventionally used to improve the surface hardness of plastic optical materials, such as polyfunctional acrylate. Examples include coatings such as hard coating agents, amino resin hard coating agents, silicone hard coating agents, and metal oxide hard coating agents, which adhere to the high refractive index transparent resin substrate without impairing its transparency. From the standpoint of obtaining a coating with excellent properties and scratch resistance, coatings of polyfunctional acrylate hard coating agents, silicone hard coating agents, and metal oxides are preferred. Polyfunctional acrylate hard coating agents are polyester compounds of polyol and (meth)acrylic acid, such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and triethylene glycol di(meth)acrylate. ) acrylate, trimethylolpropane tri(meth)acrylate, tri(meth)acryloyloxyethyl isocyanurate, glycerin tri(meth)
One or more of acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and α,ω-di(meth)acrylate-(bistrimethylolpropane)-tetrahydrophthalate. The hard coating agent can be applied to the surface of a high refractive index resin substrate, dried if necessary, and then cured to form a cured coating layer. Curing can be easily carried out by active energy rays such as ultraviolet rays and electron beams, or by heating, and in this case, for example, photopolymerization initiators such as benzoin ethyl ether, or radical polymerization initiators such as benzoyl peroxide and azobisisobutyronitrile are used. An appropriate amount of agent may be included. Silicone hard coating agents are organic silicon compounds that have two or more hydrolyzable groups directly bonded to silicon atoms in their molecules, such as tetramethoxysilane, tetraethoxysilane, trimethoxymethylsilane, triethoxymethylsilane, and trimethoxyethyl. The hard coating agent is mainly composed of one or more of silane, dimethoxydimethylsilane, jetoxydimethylsilane, tetrachlorosilane, trichloromethylsilane, etc., and the hard coating agent is applied to the surface of the high refractive index resin base material.
If necessary, it can be dried and then heated and cured to form a cured coating layer. At that time, an appropriate amount of a curing catalyst typified by para-toluenesulfonic acid may be included. Examples of metal oxides include zirconium oxide, titanium oxide, silicon oxide, and aluminum oxide, and the metal oxides are applied to the surface of a high refractive index resin base material by vacuum evaporation, sputtering, ion blasting, etc. A hardened coating layer can be formed.

The optical material of the present invention is formed by forming the above-mentioned (P,) polymer into a desired shape and forming the above-mentioned cured coating layer on the surface of a high refractive index transparent resin base material. In addition to being made of polyfunctional thioacrylate or thiomethacrylate, the base material itself has high hardness and good heat resistance.
Since the curing temperature of the thermosetting hard coating agent can be set high, the hardness of the hard coating layer is high and the adhesion of the cured coating layer to the resin base material is high.

Further, in order to further improve the adhesion with the hard coat layer, primer treatment, plasma treatment, etc. may be performed, and the obtained optical material may be laminated with an antireflection coat or film if necessary.

<Effects of the Invention> The optical material provided by the present invention has a high refractive index, is colorless and transparent, has excellent scratch resistance, and also has excellent heat resistance, cutting workability, adhesion to hard coat, etc. For example, it can be used as a base material or member for lenses, prisms, optical disks, optical waveguides, etc., and can also be used for color screens, decorative objects, and molded materials for building materials by adding pigments, fillers, etc. The present invention provides an optical material having such characteristics.

<Example> Hereinafter, the present invention will be specifically explained with reference to Examples.

Reference Example 1 A mixture of 100 parts by weight of 1.2-bis(methacryloylthio)ethane and 0.5 parts by weight of 2,2'-azobis-(2,4-dimethylvaleronitrile) was placed between two glass plates and silicone rubber. The mixture was poured into a mold made of a manufactured gasket and heated at 50°C for 5 hours and at 60°C for 15 hours.

Further, the mixture was heated at 90° C. for 2 hours to polymerize. The obtained high refractive index resin base material [a] (thickness: 3 mm) was colorless and transparent.

Example 1 After washing the high refractive index resin base material (a) obtained in Reference Example 1 with isopropyl alcohol, 20 cII of thermosetting silicone hard coating agent (N5C-1000 manufactured by Nippon Fine Chemical Co., Ltd.) was applied.
Application was done by dipping at a pulling rate of L/min.

After air-drying this plate for 30 minutes, it was baked at 120°C for 2 hours to form a hardened film layer and form a high refractive index optical material (A
) was obtained. This high refractive index optical material (A) was colorless and transparent, and no deformation or cracking was observed. This high refractive index optical material (
The physical properties of A) are shown in Table 1.

Reference Example 2 Bis-(2-methacryloylthioethyl) sulfide 5
0 parts by weight, 40 parts by weight of styrene, 10 parts by weight of acrylonitrile
A mixture of o, i parts by weight of 2,2′-azobis-(2,4-dimethylvaleronitrile) and 0.1 parts by weight of 1.1′-azobis(cyclohexane-1-carbonitrile) was used as a reference example. Pour into the same mold as in 1, heat at 50°C for 3 hours, gradually raise the temperature to 110°C over 2 hours, and further heat at 110°C for 2 hours to polymerize.
I let it happen.

The obtained high refractive index resin base material [b] (thickness: 3) was colorless and transparent.

Example 2 The high refractive index resin base material (b) obtained in Reference Example 2 was treated in the same manner as in Example 1 to obtain a high refractive index optical material [B]. This high refractive index optical material CB) was colorless and transparent, and no deformation or cracking was observed. The physical properties of this high refractive index optical material (B) are also shown in Table 1.

Example 3 After washing the high refractive index resin base material (b) obtained in Reference Example 2 with isopropyl alcohol, a polyfunctional acrylic hard coating agent (Fujino-do manufactured by Fujikura Kasei ■) was pulled up at 20 cm/min. It was applied by speed dipping. This plate was dried with infrared rays for 5 minutes, cooled, and then irradiated with a UV lamp for 1 minute to form a cured film layer to obtain a high refractive index optical material (C). This high refractive index optical material [C] was colorless and transparent. The physical properties of this high refractive index optical material (C) are also shown in Table 1.

Example 4 After cleaning the high refractive index resin base material (b) obtained in Reference Example 2 with isopropyl alcohol, a hard coat of zirconium oxide was applied by vacuum evaporation to form a hardened film layer to obtain a high refractive index optical material. CD) was obtained. This high refractive index optical material CD
) was colorless and transparent. The physical properties of this high refractive index optical material CD) are also shown in Table 1.

Comparative Example 1 The high refractive index resin base material (a) obtained in Reference Example 1 was designated as a comparative high refractive index optical material [A'], and its physical properties are also shown in Table 1.

Comparative examples 2 to 4 The physical properties of each are also shown in Table 1.

Reference Examples 3 to 15 In Reference Example 2, the same operations as in Reference Example 2 were repeated except that the composition of the polymerizable monomer component was the same as shown in Table 2.
The mixture was returned to obtain high refractive index resin base materials (C) to (0).

Examples 5 to 17 High refractive index resin base materials (C) obtained in Reference Examples 3 to 15
0], and formed a cured film layer shown in Table 2 on each to obtain a high refractive index optical material [E''l~(Q), and the physical properties of each are shown in Table 2. Examples 1 to 4 show how to use each hard coat agent to form a coating layer.
According to the method of

(Note) Physical properties were evaluated using K as follows.

0 refractive index...measured using an Atsube refractometer.

0 Total light transmittance: Measured using a turbidity meter.

The degree of adhesion was judged based on the following criteria.

A: Even if you rub it hard, there will be no scratches at all, or there will be only a slight scratch.

B: If you rub it too hard, it will get scratched.

C...It will cause damage.

0 Heat resistance... The sample was placed in a hot air dryer at 120°C for 3 hours, and the degree of deformation such as warp and coloring was observed.

Those with no deformation or coloring are marked with an ○, and those with deformation are marked with an X.

Q Adhesion: A goblin test (removal of cellophane tape) was performed, and those with no peeling were marked with ○, and those with some peeling were marked with Δ.

In addition, the abbreviations in the column of polymerizable monomer composition in the table represent the following polymerizable monomers.

BMTE 1.2-Bis(methacryloylthio)ethane BMTEE Bis-(2-methacryloylthioethyl)ether BMTES
Bis-(2-methacryloylthioethyl) sulfide BMTEE 1,2-bis-(2-methacryloyldioethoxy)ethane BMTMB 1,4-bis(methacryloylthiomethyl)benzene BzMA Benzyl methacrylate 3t Styrene TBPMA 2,4,6- 1-ribromophenyl methacrylate Br4B MEPP 2+2
-bis-(3,5-dibromo-4-methacryloyloxyethoxyphenyl)propane

Claims (1)

[Scope of Claims] 1. One or two polyfunctional thioacrylates or thiomethacrylates (hereinafter referred to as polymerizable monomer [I])
Species or more are essential components, and if necessary, the polymerizable monomer [
A cured film layer is formed on the surface of a high refractive index transparent resin base material made of a (co)combination obtained from a polymerizable monomer component containing [I] and another polymerizable monomer [II] that can be radically copolymerized. An optical material characterized by being profitable. 2. As the polymerizable monomer [I], the following general formulas (1) to (
The optical material according to claim 1, which uses at least one selected from polyfunctional thioacrylates and thiomethacrylates shown in 3). (Note) General formula (1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1 and R_2 are H or CH_3, R
_3 and R_4 are each independently H, CH_3 or OH, k and m are each independently an integer of 1 to 5, l
and n are each independently 0 or an integer of 1 to 4. ) General formula (2) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1, R_2 and are the same as in general formula (1), and X is O or S.) General formula (3 ) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1 and R_2 are the same as in general formula (1), and R_5 is a phenylene group, xylylene group, or a nuclear-substituted phenylene group, xylylene group. 3. The optical material according to claim 1 or 2, wherein the polymerizable monomer [I] is used in an amount of 5% by weight or more in the polymerizable monomer component. 4. The optical material according to any one of claims 1 to 3, wherein the cured coating layer is a thermosetting silicone-based cured coating. 5. The optical material according to any one of claims 1 to 3, wherein the cured coating layer is a polyfunctional acrylate cured coating. 6. Claim 1, wherein the cured coating layer is a metal oxide-based cured coating.
3. The optical material according to any one of 3 to 3.